A 65-year-old woman who claims she was fired after she refused to retire from her sales job at a local automobile dealership has filed suit so she can work for a competitor.

In a lawsuit filed this week in state District Court in Harris County, Carolyn Cross, a longtime manager for Sonic Automotive, claims she should not be bound by a noncompetition agreement because she was terminated without cause.

A Sonic Automotive representative did not respond to a request for comment.

The lawsuit says Cross managed Houston-area dealerships Lone Star Chevrolet, Lone Star Ford and Ron Craft Chevrolet-Cadillac for Sonic. Cross started in the business in 1967, the lawsuit says, and had worked for Sonic since 2001, when it purchased a dealership where she was a manager.

In April, the lawsuit claims, Sonic's manager asked Cross to retire and then fired her when she refused. It says the manager told employees that Cross was fired because her dealership was "underperforming."

Cross has been hired by another dealership, but the lawsuit says a letter from Sonic informed her she must abide by the noncompetition agreement until April 2014.